High-level defence talks - with Iran at the top of the agenda - took place this week in Britain and Israel as reports of a possible strike against Iran's nuclear programme intensified.

Defence Minister Ehud Barak arrived in London on Wednesday for talks with his UK counterparts, immediately after a visit to Israel by the Chief of the Defence Staff, General Sir David Richards.

The talks took place as reports suggested that Britain was ready to back the US in a possible strike on Iran.

No official details were released in either country regarding Mr Barak's meetings with Defence Secretary Phillip Hammond and National Security Adviser Sir Peter Ricketts, or General Richards' talks with the IDF Chief of Staff, Lieutenant-General Benny Gantz. But a senior Israeli official said that "naturally, at these meetings, the Iranian situation is at the top of the agenda."

General Richards' visit to Israel was kept secret until after he left the country and comes barely a year after the visit of his predecessor, Air Chief Marshal Sir Jock Stirrup.

These two visits took place after a decade in which Britain's most senior soldier did not visit Israel. They underline the increasingly close defence and intelligence relations between the two countries which have remained strong, despite sometimes tense diplomatic relations.

The mutual visits took place at a time when both the British and Israeli media are reporting the possibility of military action against Iran, either by Israel on its own or by the United States, aided by Britain. It is rare that a public debate on the pros and cons of an Iran strike takes place in Israel.

It is not yet clear whether Israel has made the decision to attack, but Mr Barak told the Knesset on Tuesday that the recent developments in the Middle East could "lead to situations in which Israel will have to defend its interests or act on our own, without needing to rely on regional powers or others for help."

The Iranian dilemma came to the forefront early last month when US Defence Secretary Leon Panetta visited Israel and Egypt and said in Tel Aviv that the US was "very concerned, and we will work together to do whatever is necessary to keep Iran from posing a threat to this region." But doing so "depends on the countries working together," he added.

Mr Panetta's statement was seen in the Israeli media as a warning from the Obama administration concerned that a decision has already been made in Israel to attack Iran in the near future.

The timing of this debate is no coincidence. Next week, the International Atomic Energy Agency is scheduled to publish a new report on Iran's military nuclear programme. At the same time, Israeli military experts believe that the chances of a successful airborne attack on Iranian installations during the winter months are dramatically lower.

Talk within defence circles of this "window of opportunity" has led to speculation that Mr Netanyahu's willingness to sign off on the controversial Shalit prisoner exchange deal was a "clearing of the table" before a possible attack on Iran. Both Mr Netanyahu and Mr Barak are known to favour an attack on Iran, while previous chiefs of the IDF and Mossad have said over recent months that sanctions and other methods should still take precedence over military actions.

The current chiefs are also believed to be reluctant to launch a strike now without US support. At least half of the "Octet," the Israeli cabinet's senior decision-making forum, is also currently opposed to an attack. One of its members, Benny Begin, said on Wednesday that carrying out such discussions in public was "obscene."

While Israel's leadership is not prepared to admit to preparations, the IDF has been unusually open about details of a large-scale exercise its combat jets carried out last week with NATO air forces, 1500 miles from Israel's borders, over Sardinia.

In addition, on Wednesday the Defence Ministry carried out a test-launch of a ballistic missile over the eastern Mediterranean, and the IDF launched a civil defence exercise, simulating a missile attack on Tel Aviv.

The ministry insists that all these were planned months in advance, but their public revelation together is hardly pure coincidence.

Responding to media reports about the visit to Israel of the British Chief of the Defence Forces, a Ministry of Defence spokesperson said: "General Sir David Richards was visiting Israel for a planned, routine trip."

Privately, senior MoD officials flatly refuted suggestions that Britain was ready to be part of a US-led attack on Iran.